Indian security & counter-intelligence officials believe the mastermind behind the Pulwama terror attack is most likely Mohammed Umair, the son of Athar Ibrahim, who is the elder brother of Jaish-e-Mohammad founder and chief Masood Azhar. While the bomber, 22-year-old Adil Ahmad Dar, was killed, officials have added that the bomb-maker is at present hiding in Muzaffarabad in Pakistan-occupied-Kashmir (PoK).